The UWCCC Analytical Instrumentation Laboratory (AIL) provides a resource for bioanalytical chemistry and pharmacology studies to all UWCCC investigators. These services are important to many programs of the UWCCC, including those involved in clinical trials of new drugs and chemopreventative agents; studies of biochemical markers of drug effect and toxicity; and studies of mechanism of drug action and metabolism. In the last decade, pharmacokinetic/pharmacodynamic (PK/PD) studies have become an integral component of early clinical trials. The facility has the capability of setting up and executing a wide variety of assays as they are needed for new studies and can also offer many of the analytic assays of an ongoing basis as drugs move from early Phase I into Phase II and combination trials.